Many people who have had a seizure do not remember it. Afterward, they may feel confused and drowsy, have a headache, or be nauseous.

Doctors often call this a postictal state.

Usually, the brain produces a continuous, orderly pattern of electrical impulses. These impulses travel along a network of nerve cells, or neurons, passing messages to the rest of the body. A seizure happens when something changes the pattern of these electrical charges.

There are different types of seizures, and they have different symptoms. However, because seizures can affect memory, some people who have seizures do not remember them.

Read on to learn more about the signs that a person has had a seizure.

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It can be hard to tell whether someone has had a seizure. It depends on the person and the type of seizure. Around 30% of people with seizures do not remember them, and just 25% of people remember every one of them.

The period of time after a seizure is called the postictal state. It starts as the seizure improves and ends when the brain’s electrical impulses return to normal. It may last 5–30 minutes.

During this time, a person may have a range of symptoms that can be disorientating. These may include:

  • confusion
  • drowsiness
  • high blood pressure
  • headache
  • nausea
  • coughing
  • producing more saliva than usual
  • producing more nose mucus than usual

Some people may experience the following:

  • psychosis, meaning they become unable to recognize reality
  • mania, meaning they feel excessively happy, overactive, or obsessed

There are several different types of seizures, and each has distinct symptoms. Doctors classify seizures according to the part of the brain they affect.

The two main categories of seizures are:

  • Generalized seizures: These affect both sides of the brain.
  • Focal seizures: Also known as partial seizures, these affect just one part of the brain.

The two types of generalized seizures are:

  • Absence seizures: These can cause someone to blink rapidly or stare into space for a few seconds. Doctors sometimes call them petit mal seizures.
  • Tonic-clonic seizures: These cause people to cry out and fall to the ground with muscle jerks or spasms. They also lead to unconsciousness.

There are three types of focal seizures:

  • Simple focal seizures: These affect a small part of the brain and can cause twitching or changes in taste or smell.
  • Complex focal seizures: These can cause confusion. A person might be unable to answer questions or follow instructions.
  • Secondary generalized seizures: These start in one part of the brain and then spread to the other side of the brain. The symptoms will be different for everybody but will include some combination of the above.

Seizure causes are wide-ranging and include:

  • low sugar levels
  • low sodium levels
  • high sodium but low water levels
  • low calcium levels
  • drug side effects
  • withdrawal, such as from alcohol or antidepressant medications
  • sepsis
  • infections of the central nervous system
  • lack of oxygen to the brain
  • brain injury
  • stroke
  • brain tumor
  • brain inflammation, or swelling
  • fever
  • sleep deprivation

If a person has at least two seizures that were not caused by any other medical condition, doctors may diagnose epilepsy. In around 50% of epilepsy cases, doctors cannot find the cause.

Learn more about epilepsy.

Treatment depends on the cause of the seizure. When something other than epilepsy is the cause, doctors will treat the underlying condition.

There is no cure for epilepsy, but people can manage it.

For most people, taking antiepileptic medications (AEDs) can control seizures. There are many different AEDs, and a doctor will usually talk a person through their options and recommend the best one for them.

However, in around 30% of people, AEDs do not work. When this is the case, doctors may suggest surgery to remove the part of the brain causing the seizures.

Learn more about treatment options for epilepsy.

Anyone who suspects they may have had a seizure for the first time should speak with a doctor as soon as possible.

The American College of Emergency Physicians recommends calling 911 if:

  • the seizure lasted 5 minutes or more
  • the seizure caused injuries
  • the person is pregnant
  • the person has diabetes
  • the person experiences any of the following:
    • persistent difficulty breathing
    • fever
    • confusion
    • loss of consciousness

Seizures happen when something interrupts the electrical impulses in the brain.

Many people do not remember having a seizure. This is part of what doctors call the postictal state, which tends to last for 5–30 minutes afterward. A person may feel confused and drowsy, have a headache, or feel nauseous.